topic Float number problem in LPC Microcontrollers

Float number problem

Alexshea — Mon, 18 Apr 2022 05:13:06 GMT

Hello everyone, my code used to work fine, but I changed the chip and added some new lines to my code. I used to read two temperatures (LM35) from ADC and I want my data to be float. Now instead of dot it shows temperatures with something similar to a y with two dots on top of it. For example instead of showing 25.3 it shows something like 25y3. I can show the temperatures in integer correctly, but when I change the data to float it shows something weird like 25y3. It used to work fine. I added my code and the screenshot of the bluetooth app. Btw my chip is LPC1768

Thanks in advance,

Alex

Re: Float number problem

Alexshea — Mon, 18 Apr 2022 05:31:10 GMT

@xiangjun_rong Hi, could you please help me? I showed this code to you many times. Someone else also told me my float variables shouldn't have that much zeros.

Re: Float number problem

Alice_Yang — Wed, 20 Apr 2022 02:00:02 GMT

Hello Aleshea,

How about use another terminal to show result?

Alice

Re: Float number problem

Alexshea — Wed, 20 Apr 2022 20:16:13 GMT

Thank you for the reply. Actually, I tried that with LabVIEW too. Problem wasn't with the Bluetooth terminal. Interestingly, it works fine when I use only uart3, but when I activate uart1 it messes up float numbers. I could send them as uint and instead of sending the data in float I sent them in uint and devided it by 10 in LabVIEW, so that I can see the data in LabVIEW like float numbers. So, I bypassed this problem, though still it's good to know why activating uart1 messes up the data in float

Re: Float number problem

xiangjun_rong — Thu, 21 Apr 2022 02:26:48 GMT

I think you can consider to change the library or the float number format as the following screenshot.

1)change the library

Setting->Miscellaneous->library header

2)change the float format

Setting->Architecture->Floating point.

Hope it can provide a clue.

Hope it can help you

XiangJun Rong

Re: Float number problem

Alexshea — Thu, 21 Apr 2022 20:19:02 GMT

Thank you so much. I think it'll work this way. I sent the data in uint16 and change it into float in LabVIEW, but I may face this problem again and can try what you recommended